Alloy



Patented Jan. 2, 1940 UNITED STATES PATENT- OFFICE ALLOY Elmore S.Strang, New Haven, and Richard 0.

Farmer, Seymour, Conn., and Edward H. Kocnig, West Orange, N. J.,assignors to The New Haven Copper Company, Seymour, Conn., a corporationof Connecticut No Drawing.

Application August 10, 1938,

Serial N0. 224,136

4 Claims.

: This invention relates to alloys and more particularly to a copperbase alloy and to a process of producing the same.

A feature of the present invention is the production of-a copper-basealloy which has increased corrosion resistance, hardness and strength ascompared to copper, which can be either hot worked or cold worked, whichis more tough and ductile and which has other physical characteristicssuperior to known copper alloys.

Another feature of the invention consists in the addition to acopper-base alloy containing silicon, of sufiic-ient nickel to enhancethe tough- In accordance with an illustrative embodi-' ment of theinvention an alloy having desirable characteristics can be prepared asfollows:

Copper, silicon and manganese-copper in amounts which will produce inthe finished alloy from around 90% to 98% copper, from around 1% to 7%silicon and from around .10% to .75% manganese are charged in a crucibleor furnace, melted and suitably mixed.

When the above materials have been melted and mixed, sumcient nickel isadded which will produce in the finished alloy a nickel content of from25% to 10%. Preferably, the nickel is introduced in such amounts as willgo into solution quickly and with no increase in temperature of themolten bath. The introduction of the manganese before the nickel,reduces the melting point of the mix and permits the nickel to be addedat a lower temperature than if the nickel were introduced first.

At the same time that the nickel is added to the melt, iron is added inan amount sufiicient to give a residual iron content in the finishedalloy manganese-copper is added to the first mix, so that the totalmanganese content of the finished alloy is from .10 to .75%. Addition ofthe small additional manganese-copper insures that the resulting castingwill be sound and free of inclusions of oxides or gases.

It is desirable that the mix be melted at a temperature of above 1150 C.Before pouring, the melt preferably is allowed to cool to a temperaturebetween 1120 C. minimum and 1140 C. 10

maximum in order to obtain a sound casting without pipe and which doesnot spew when freezing. In pouring the melt, it is desirable to use apouring cup for filling the mould inorder to distribute the metal evenlyas it flows into the mould and to assist in shrinking the-bar, that is,teeming or filling the mould from time to time with additional metal asshrinking occurs, in order to prevent piping.

Where it is desirable that the finished alloy be readily machinable,lead is added in small amounts sufiicient to give a lead content in thefinished alloy of approximately .10 to .50%. However, it is desirableonly to add lead where machinability is an important requirement. Wherelead is added, is preferably is added to the mix only a short timebefore pouring, in order to prevent loss of lead'by'oxidation.

We have found that by the addition of nickel to the copper-silicon alloyand by the cleansing effect obtained by the additions ofmanganesecopper,it is possible to obtain in soft material a tensile strength in excessof 70,000 pounds per square inch with a yield point of 30,000 pounds persquare inch and an elongation of 50% in two inches, with the necessityof any particular heat treatment in the fabrication of the materialother than ordinary process anneals.

This alloy can be hot rolled or forged at a temperature of at least 100F. higher than the temperature at which many other copper-silicon alloyscan be rolled. For example, this alloy can be rolled at a temperature ofaround 1600 F. which permits greater reductions between heats thanheretofore possible.

We have also found that at the critical temperature of annealing thisalloy, namely, 1500 F., without quenching, the material is sufflcientlysoftened to permit stretching, or patent leveling and flattening whencold. The material, however, retains a Rockwell B scale ,4 ball hardnessof to with an elongation of the order of 50% and a tensile strength ofaround 70,000 pounds per square inch. This alloy will permit a greateramount of economical cold work than many of the usual copper-siliconalloys.

We have found further, that when this alloy is cold worked afterannealing a tensile strength in excess of 120,000 pounds per square inchcan be obtained with a yield point of at least 60,000 pounds per squareinch and an elongation of not less than 3% in two inches. The modulus ofelasticity of the material is 18.8 x 10 The alloy is inherentlyresistant to corrosion and is at least equal to or, in some cases,superior to usual copper-silicon alloys in this regard. By reason of thegreat hardness of this alloy, which is obtained without special heattreatment, the alloy has a very high resistance to abrasion. Thematerial produced in accordance with the invention has a relatively lowelectrical conductivity, namely, around 6%.

Sonle of the commercial uses for this alloy are:

tanks or boilers for water or chemicals; paper print rollers on whichdesigns-are etched; paper mill equipment, such as paper pulp chests,screen, plates, Jordan or beater bars; leaf springs for electricalcontacts and for mechanical uses; thrust bearings for taking shocks;sanitation equipment; textile equipment; turbine blading; pump linersand rods, etc. The alloy can be readily welded electrically and the weldor seam has exceptionally high strength and resistance to corrosion.

Although the percentage composition of the alloy set forth above hasbeen found preferable, nevertheless, it is possible to produce adesirable alloy in accordance with the invention by departing from theranges set forth above. In general, the alloy should contain asufiicient proportion of silicon to render the alloy resistant tocorrosion and to produce a tensile strength substantially greater thanthat of copper. In order to obtain maximum hardness it is necessary thatthe alloy contain a minimum of 3% silicon. It is also desirable that thealloy contain at least .5% each of iron and manganese. The alloy alsoshould contain a sufiicient proportion of nickel to render it workableand tough. The alloy should contain .25-10 nickel and preferablyapproximately .5%,

From the foregoing it will be seen that we have produced a copper-basealloy which has high corrosion resistance, hardness, tensile strength,toughness, ductility, and elasticity, which can be either hot worked orcold worked and which has a low electrical conductivity.

While certain novel features of the invention have been disclosedherein, and are pointed out in the annexed claims, it will be understoodthat various omissions, substitutions and changes may be made by thoseskilled in the art without departing from the spirit of the invention.

What is claimed is:

1. An alloy composed of from 1-5% silicon, approximately one-half of oneper cent each of nickel, iron and manganese, and the balancesubstantially all copper, which is corrosion and abrasion resistant.

2. An alloy containing substantially 95 of copper, 3% of silicon, theremainder being onehalf of one per cent each of nickel, manganese, andiron, which is more than ordinarily ductile and elastic as compared toits strength and hardness, and which is corrosion and abrasionresistant.

3. An alloy composed of 25-10% nickel, 1.0- 7.0% silicon, approximatelyone-half of one per cent of manganese and approximately one-half of oneper cent of iron, and the remainder substantially all copper, which canbe annealed at 1500 F., and without quenching produce a material whichcan be easily cold rolled, stretched, or patent leveled and flattenedand still retain a Rockwell B scale, ,5 ball hardness of 60 with anelongation of and a tensile strength of 70,000 pounds per square inch.

4. A copper base alloy composed of from about 1.0-7.0% silicon, fromabout 0.25-10.0% nic from about 0.5-0.75% iron, from about 0.l-0.75%manganese and the remainder substantially all copper.

ELMORE S. S'I'RANG. RICHARD O. FARMER. EDWARD H. KOENIG.

